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240 IGUANA  •  VOLUME 12, NUMBER 4  •  DECEMBER 2005 GUTSCHE

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Norops utilensis 1 is endemic to the Isla de Utila (Islas de la
Bahia, Honduras). Discovered in 1995, it is a poorly

known member of the N. pentaprion-group. In contrast to the
other members of the group, all of which live in broadleaf trop-
ical rain forests, N. utilensis dwells exclusively in a highly spe-

The World’s Most Endangered Anole?
Alexander Gutsche

Department of Biology, Sensory Biology, Humboldt-University
Berlin, Germany

Photographs by the author unless otherwise indicated.

IGUANA  •  VOLUME 12, NUMBER 4  •  DECEMBER 2005 241WORLD’S MOST ENDANGERED ANOLE?

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1 In 1987, Craig Guyer and Jay Savage (Systematic Zoology 35:
509–531) proposed a classification of anoles that included formal
recognition of several distinct genera within the group. One of these
genera was Norops, to which the Utila Anole has been assigned.
Although recognition of those genera has been strongly advocated
by some authorities, others, who would refer to the Utila Anole as
Anolis utiliensis, prefer a more conservative approach until a number
of concerns regarding generic relationships among anoles have been
addressed. Those concerns were best summarized by Ernest Williams
in 1989 (In: C.A. Woods (ed.), Biogeography of the West Indies: Past,
Present, and Future. Sandhill Crane Press, Gainesville, Florida).

An adult female Utila Anole (Norops utilensis).

Because suitable nesting holes are a limited resource in the mangrove
forests, Utila Anoles may lay their eggs communally. The two shells in
this nest hole in a hollow Red Mangrove root are remains of eggs that
were undoubtedly laid by two different females.



cialized habitat – the salty mangrove swamps of Isla Utila (see
Iguana 12:142 for detailed descriptions of the habitat).

Norops utilensis is a medium-sized anole, reaching about
150 mm in total length, most of it tail (maximum known

snout-vent length = 59 mm). They are well-camouflaged due
to a lichenose gray-brown dorsal pattern, which makes them
difficult to detect as they adhere closely to the surface of man-
grove trunks and branches. A red dewlap is present in both

242 IGUANA  •  VOLUME 12, NUMBER 4  •  DECEMBER 2005 GUTSCHE

One-day-old hatchling Utila Anole at the egg-laying site (tree hole in a Rhizophora mangle root).

Natural habitat of Norops utilensis at the type locality: A mixture of
Black (Avicennia germinans) and Red Mangroves (Rhizophora mangle).

A Common Black Hawk (Buteogallus anthracinus) in the Big Bight, one
of the areas where Norops utilensis is known to occur. Although these
hawks typically prefer larger prey (including iguanas), they might occa-
sionally take an anole. Predation pressure from visual predators may
contribute to the cryptic coloration and shy behavior of Utila Anoles.

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IGUANA  •  VOLUME 12, NUMBER 4  •  DECEMBER 2005 243WORLD’S MOST ENDANGERED ANOLE?

males and females, but is much larger in males and forms a
bright shining signal flag when they respond to intruders or
advertise their presence to females. Utila anoles are entirely
arboreal and live and behave in a gecko-like fashion, pressing
their bodies tightly against the substrate as they cling closely to
the surface of mangrove trunks and twigs at heights ranging
from 1–7 m above the waterlogged ground.

Like most anoles, females lay a single egg at a time, using
suitable, detritus-filled tree holes. These tree holes are a limited
resource within the mangroves; consequently, communal nest-

ing appears to be common. Although the local climate is strictly
seasonal (with distinct wet and dry seasons), N. utilensis repro-
duces throughout the year. Most reproductive activity occurs
during the rainy season (when food is presumably most plenti-
ful), but individuals quickly become reproductively active dur-
ing periods in the dry season when favorable conditions exist.

Norops utilensis is not common in the mangrove swamps.
Since its discovery, only 13 specimens have been detected at
two localities. Due to the specialized and severely limited habi-
tat, apparently low population sizes, and ongoing human
threats to the habitat (e.g., deforestation and use of the man-
grove swamps for solid waste disposal), N. utilensis meets all of
the IUCN Red List criteria (http://www.redlist.org/info/cate-
gories_criteria.html) to qualify for critically endangered status.
As for so many other threatened insular endemics, the best
chances for long-term survival lie in controlling the size of the
human population, education, and preservation of critical habi-
tats (see Iguana 10:28–37 and Iguana 11:206–211 for addi-
tional pertinent information).

References
Gutsche, A., J.R. McCranie, and K. Nicholson. 2004. Field observations on

a nesting site of Norops utilensis Köhler, 1996 (Reptilia, Squamata) with
comments about its conservation status. Salamandra 40:297–302.

Köhler, G. 1996. A new species of anole of the Norops pentaprion-group from
Isla de Utila, Honduras. Senck. biol. 75:23–31.

McCranie, J.R., L.D. Wilson, and G. Köhler. 2005. Amphibians & Reptiles of
the Bay Islands and Cayos Cochinos, Honduras. Bibliomania!, Salt Lake
City, Utah.

Utila Anoles are associated strictly with mangrove stands near the Big Bight.

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Utila Anoles rely heavily on crypsis to avoid predators and rarely extend
their dewlaps (see also inside front cover).




